/*
 * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * Ordered alphabetically using scriptname.
 * Scriptnames of files in this file should be prefixed with "npc_pet_dk_".
 */

#include "ScriptMgr.h"
#include "CellImpl.h"
#include "CombatAI.h"
#include "GridNotifiersImpl.h"
#include "MotionMaster.h"

enum DeathKnightSpells
{
    SPELL_DK_SUMMON_GARGOYLE_1      = 49206,
    SPELL_DK_SUMMON_GARGOYLE_2      = 50514,
    SPELL_DK_DISMISS_GARGOYLE       = 50515,
    SPELL_DK_SANCTUARY              = 54661
};

struct npc_pet_dk_ebon_gargoyle : CasterAI
{
    npc_pet_dk_ebon_gargoyle(Creature* creature) : CasterAI(creature) { }

    void InitializeAI() override
    {
        CasterAI::InitializeAI();
        ObjectGuid ownerGuid = me->GetOwnerGUID();
        if (!ownerGuid)
            return;

        // Find victim of Summon Gargoyle spell
        std::list<Unit*> targets;
        Trinity::AnyUnfriendlyUnitInObjectRangeCheck u_check(me, me, 30.0f);
        Trinity::UnitListSearcher<Trinity::AnyUnfriendlyUnitInObjectRangeCheck> searcher(me, targets, u_check);
        Cell::VisitAllObjects(me, searcher, 30.0f);
        for (Unit* target : targets)
        {
            if (target->HasAura(SPELL_DK_SUMMON_GARGOYLE_1, ownerGuid))
            {
                me->Attack(target, false);
                break;
            }
        }
    }

    void JustDied(Unit* /*killer*/) override
    {
        // Stop Feeding Gargoyle when it dies
        if (Unit* owner = me->GetOwner())
            owner->RemoveAurasDueToSpell(SPELL_DK_SUMMON_GARGOYLE_2);
    }

    // Fly away when dismissed
    void SpellHit(WorldObject* caster, SpellInfo const* spellInfo) override
    {
        if (spellInfo->Id != SPELL_DK_DISMISS_GARGOYLE || !me->IsAlive())
            return;

        Unit* owner = me->GetOwner();
        if (!owner || owner != caster)
            return;

        // Stop Fighting
        me->SetUnitFlag(UNIT_FLAG_NON_ATTACKABLE);

        // Sanctuary
        me->CastSpell(me, SPELL_DK_SANCTUARY, true);
        me->SetReactState(REACT_PASSIVE);

        //! HACK: Creature's can't have MOVEMENTFLAG_FLYING
        // Fly Away
        me->SetCanFly(true);
        me->SetSpeedRate(MOVE_FLIGHT, 0.75f);
        me->SetSpeedRate(MOVE_RUN, 0.75f);
        float x = me->GetPositionX() + 20 * std::cos(me->GetOrientation());
        float y = me->GetPositionY() + 20 * std::sin(me->GetOrientation());
        float z = me->GetPositionZ() + 40;
        me->GetMotionMaster()->Clear();
        me->GetMotionMaster()->MovePoint(0, x, y, z);

        // Despawn as soon as possible
        me->DespawnOrUnsummon(Seconds(4));
    }
};

struct npc_pet_dk_guardian : public AggressorAI
{
    npc_pet_dk_guardian(Creature* creature) : AggressorAI(creature) { }

    bool CanAIAttack(Unit const* target) const override
    {
        if (!target)
            return false;
        Unit* owner = me->GetOwner();
        if (owner && !target->IsInCombatWith(owner))
            return false;
        return AggressorAI::CanAIAttack(target);
    }
};

void AddSC_deathknight_pet_scripts()
{
    RegisterCreatureAI(npc_pet_dk_ebon_gargoyle);
    RegisterCreatureAI(npc_pet_dk_guardian);
}
